Transducers are used in a variety of applications including consumer electronics devices, video games, mobile communications devices, and automotive applications. In automotive applications multiple transducers, or microphones, may be coupled to an audio control system. Audio control systems are typically manufactured in an integrated circuit (“IC”) and include audio codecs, processors, and controllers which control operation of the microphones for various entertainment and/or communications applications. The audio control IC also monitors the supply lines of the multiple microphones for various faults which may occur during their operation. These faults may include shorts to various supply potential voltages, shorts to ground, supply line shorts to each other, and/or open supply line connections.
For automotive applications, operational supply potentials may be provided in a first high voltage domain, while the audio control system may operate in a second low voltage domain. For example, the first domain supply potentials may include battery voltages, which often range between 11V-18V, and/or microphone supply voltages, which often range between 1V-7V. The second low voltage domain for the audio control IC typically ranges between 3V-5V.
To detect faults on the microphone supply lines, the audio control IC is often coupled to external fault detection devices which operate in the first voltage domain. This is to ensure that shorts that may occur for voltages in the first voltage domain do not damage the audio control IC, which operates in the second voltage domain. Such external devices operating in the first voltage domain add to the complexity, cost, and power consumption of implementing fault detection for a multi-sensor system. Further, such external devices often operate in a non-linear manner and require further signal conditioning in order to properly detect faults or shorts that may occur with the sensor supply lines.
Accordingly, there is a need in the art for a fault detection system which detects faults for a variety of supply potentials within the voltage domain of the fault detection system.